class Optimist::Parser

def cloaker(&b)

# thanks to _why: http://redhanded.hobix.com/inspect/aBlockCostume.html
# instance_eval but with ability to handle block arguments 
def cloaker(&b)
  (class << self; self; end).class_eval do
    define_method :cloaker_, &b
    meth = instance_method :cloaker_
    remove_method :cloaker_
    meth
  end
end